One-cushion billiards developed in the late 1860s as an alternative to the game
straight rail, in which points are scored by a simple carom off both object balls with no cushion requirement. Straight rail fell into disfavor as skilled top players could score a seemingly endless series of points with the balls barely moving in a confined area of the table playing area. This was a result of the "rail nurse", a shot in which the object balls are nudged at very soft speed down a rail to a duplicate position again and again. Later, between 1881 and 1889, a new nurse shot was developed for one-cushion, known as the "rub nurse". With the two object balls stacked perpendicular to a rail and just next to it, the rub nurse is performed by gently banking the cue ball off the rail so it softly grazes both object balls before coming to rest near the original position. The presently-dominant game,
three-cushion billiards, a direct outgrowth of one-cushion billiards also beginning in the 1870s, did not marginalize balkline until the 1920s. The U.S. title at one-cushion billiards has only been held by six men: Joseph Dion, William Sexton, Maurice Daly, George Slosson and
Willie Hoppe, who held it for 11 years from 1933 to 1944. Today, one-cushion billiards is rarely played in the U.S., but it still enjoys some popularity in Europe where it is featured as one of the five games making up the annual billiards
pentathlons, the other four games being 47.1 balkline, straight rail, 71.2 balkline and three-cushion billiards. ==References==